Source : Webster's Revised Unabridged Dictionary (1913)

Estimate \Es"ti*mate\, v. t. [imp. & p. p. {Estimated}; p. pr. &
   vb. n. {Estimating}.] [L. aestimatus, p. p. of aestimare. See
   {Esteem}, v. t.]
   1. To judge and form an opinion of the value of, from
      imperfect data, -- either the extrinsic (money), or
      intrinsic (moral), value; to fix the worth of roughly or
      in a general way; as, to estimate the value of goods or
      land; to estimate the worth or talents of a person.

            It is by the weight of silver, and not the name of
            the piece, that men estimate commodities and
            exchange them.                        --Locke.

            It is always very difficult to estimate the age in
            which you are living.                 --J. C.
                                                  Shairp.

   2. To from an opinion of, as to amount,, number, etc., from
      imperfect data, comparison, or experience; to make an
      estimate of; to calculate roughly; to rate; as, to
      estimate the cost of a trip, the number of feet in a piece
      of land.

   Syn: To appreciate; value; appraise; prize; rate; esteem;
        count; calculate; number. -- To {Estimate}, {Esteem}.
        Both these words imply an exercise of the judgment.
        Estimate has reference especially to the external
        relations of things, such as amount, magnitude,
        importance, etc. It usually involves computation or
        calculation; as, to estimate the loss or gain of an
        enterprise. Esteem has reference to the intrinsic or
        moral worth of a person or thing. Thus, we esteem a man
        for his kindness, or his uniform integrity. In this
        sense it implies a mingled sentiment of respect and
        attachment. We esteem it an honor to live in a free
        country. See {Appreciate}.